Stuffing mechanism



Aug. 21. 1923.

o. c. SCHMIDT STUFFING MECHANISM Filed Dec. 29,1920

71 64 5s 66 y 55 I m 65 86 3 Z 4 Sheets-Sheet 1 STUFFING MEGHANI SM Filed Dec. 29, 1920 4 Sheets-Sheet 2 Aug. 21, 1923.

O. C. SCHMIDT STUFFING MECHANISM Filed Dec.

4 Sheets-$heet 5 Aug. 21, 1923.

O. C. SCHMlDT STUFFING MECHANISM Filed Dec. 29. 1920 4 sheets-Sheet 4 9 M Z 2:: 0O 7 1 l 0 iv 15 l M "0/ H :5: E: l (W Z /2 van for:

Patented Aug. 21, 1923.

i a; st Aft-E losoan o. SCHMIDT, or CINCINNATI, onIo, assrenoni'romnn CINCINNATIBUTCH'E'RS SUPPLY,GOMPAI\TY,'QE CINCINNATI, OHIO, Aoonronerron oFoHIo.

STU FFING MECHANISM.

Application filed December 29, 1920. .Serial 110 433392. 7

To all whom it may concern:- v

Be it known that 1, Oscar: C. SCHMIDT, a citizen of the United States, residing in Cincinnati,in the county of Hamilton and State of ()hio, have invented certain newand useful Improvements in S-tuffing Mechanism, of which the following is a specification,

My invention relates to stufling mechanism applicable among otherthings for stuffing sausage casings.

It is the object or" my invention to provide new and. improved means ,for [enhancing safety in manipulation of a device of this character; further, toprovidenovel means employed in cleaning the interior of the mechanism and. in supporting, the safety meansiy further, toprovide novel arrange.

ment o'fymeans' 'for counterbalancing the rcover of the device; further, to provide novel means for securing the cover in place and for employing the securing means to balance the cover when opening and-closing the latter; further, to provide novel means for con-, trolling the opening and closing of the cover; and, further, to provide no-velpresshead mechanism in a device of this character. The invention will be further readily understood from the following description and claims, and from the drawings, in which latter:

Fig. l'is a side elevation of my improved device, partly broken away for better illustration of parts. 7 l r Fig. 2 is a plan view of the same.-

is'an" end elevation otthe same, partly in central axial section, on the line 3-3 of Fig. 2, for better illustration" of parts. I

Fig. 4 is a side elevation of thepressure safety mechanism of my improved device. Fig. 5 is a frontelevation-of the same. Fig. 6 is a horizontal section of my improved device taken in the plane of the line 66 of Fig. 7, partly broken away.

Fig. 7 is a central axial section of a detail of mv improved device. takenin the plane of the line 'T7 of Fig. 6, showing the presshead in lowermost position, with its packing in retracted relation.

Fig. 8 is a detail of the operated end of the pressure safety mechanism, taken on the line S-8ofFig.5.

Fig. 9 is a horizontal section of the same, taken in the plane of'the line 99 of Fig.8.

F 10 is a central axial oi the stufling valve, taken on the, line 10 l0 of Fig. 2.

Fig. 11 is a vertical section of a detail ot I the securing mechanism for the cover, taken on thehnelL-ll of Fig.3. f F g. 12 is a cross section of the sa fety con.-

trol valvelfor controlling the operation of in the plane ofthe-line the cover. taken 12- 12of Fig. 13. r l

Fig. 13 is an axial section of the same,

taken in the plane of the-line 13-1301 Fig. 12.

Fifi. .14 isia s ctional detail-taken on aie j finale-14 ot-Figfi; and, F1g. 15 is an enlarged V se tiona-l detailv the press-head.

A press-head is employed-in mechanism of this characten'operable-in a cylinder,for i' the purpose:otforcing plastic material, For; instance, chopped; and prepared sausage meat or,.as it is called, meat dough, through a nozzle or nozzles into, so-called saus'agecasings. Themeat'dough is placed at one side of the press-head, .while pressure, preferably.

fluidpressure, is" employed at the other side of the press-head, for forcing-the material throughthe nozzle or nozzles. The pressure required depends in great measure upon the consistency'of the meat doughorplastic ma.- terial. This-is, at times very great. It has happened'in operations of devices of this character that thepress-head has-been blown out of the cylindei by the pressure behind it.

It is also desirable, in a deviceofthis char acter, that the; interior of the cylinder and the parts of the mechanism connecting therewith shallbe readily accessible'for the pur' pose of'cleaningi and attention to the parts." lhave also found it desirable" to providea simple press-heacl2employing few parts. and provided with a packing so arranged that' its diameterwill automaticallydecrease upon retraction of thepressrhe'aiand automatically I increase in simple manner upon 'movement of. the press-head. in opposite directions, for

forming a close joint betweenf-the presshead and-the inner face ofthe wallof the cylinder, to prevent the leaking of material the improvements which" I- have invented in a device ofthecharacter mentionedflyshall now more particularly describe an exempli fication'of the same, having reference to the exemplification shown in the drawings.

A casing 21 has a press-head 22 operable therein. The casing is shown as an upright cylinder. It-has a bottom 23, suitably secured to the wall of the casing by bolts 24.

A nozzle 25 communicates withthe upper portion of the casing, as through a valve 26, having 7 attachment, as by means of a threaded connection 27 with a port 28. The

I I nozzle is releasable so that nozzles of various designated by similar reference numerals.

The plastic material or meat dough is placed in the casing above the press-head. The fluid pressure, for instance compressed air, water or steam, is introduced into the casing below the press-head, whereby the pressure thereby exerted acts to raise the press-head, and thereby force the plastic material through the nozzle. .The fiuid isexemplified as introduced 'into the casing through a port 35, with which apipe 36 communicates, a valve37 opening'and shutting off or regulating the supply .of pressure through the pipe, this valve being provided with safety control'means forcontrolling the opening of the cover. The safety control means are exemplified as an arm 38, the arm and the valve-plug being operable bymeans of a handle 39, and'acting in manner hereinaftermore particularly described.

The casing is arranged to be closed by a cover 41, pivotedat 42 to. the casing, as'by means of providing the cover with a hear-- ing 48' and the casing with bearing-lugs 44. The pivot-pin is received through the bearings of the bearing-lugs and the bearing of the cover for permitting swinging of the cover. There is preferably a taper joint 45 betweenthe cover'and the casing, so as to formv a close joint between the same when the cover is closed.

A yoke 4:8.is pivoted on studs 49 extending-from the casing or cylinder, as by having the casing and a cross-piece'54 arranged to be received 'over'the cover, The yoke is preferably substantially a heavy casting.

This yoke V aids in counterbalancing the cover, in'manner presently to be described, when it is desired to open the cover.

The cover is provided with ahump 57 having a contact-face 58, shown as an areface. The hump 'is showngon an arm 591 7 attached to the cover proper'by bolts 60.

The contact face corresponds substantially ing 64, secured, as by a set-screw 65, in the.

bearing (56 of the yoke. The bushing is provided with a fiange 67 received in a recess 68 in the lower partof'the bearing 66 for resisting the force of; the pressure when clamping the cover. The plug is held to the threaded clamping rod by means of a screw 69, the clamping rodbeing preferably rotatable on said plug. Handles 71, preferably provided with weights 72, are fixed to the threaded rod forconveniently' operating the same, and exerting force to force the cover toward the-casing for firmly clamping the cover tothe casing.

The cover is provided with a portion arranged to be acted upon by the yoke for aid- 1 ing in counterbalancing thescover. This portion of the cover is at that side of the pivotfor the cover opposite the side thereof :at which the coverlproper is located. This cover-portion is shown as an extension 75 of the arm 59, having a face 7 6 arranged to be contacted by the yoke when the yoke is moved into release position. This face is shown as a curved recess. The curve of this recess and the arc ofcurvature of the contact portion of the cover, are shown as forming an ogee-like contact-face, the'outer end of which, in the present exemplification, forms a resting 'face for the yoke when the yoke is moved intoextreme release position,

as indicated in dotted linesin Fig. 1. The yoke is adapted to contact and move along the contact-face, and to rest on the rear portion of this face.

For further aiding in the operation of'the .coverin opening and closing thesame, I provide a spring 78 between the rearward extension of the cover and a bracket 79 extending from the cylinder or casing. This spring is so positioned and located as to act as a cushioning means for the cover at the ends of the movements of the same when opening and closing the cover. I This spring is shown as atension spring, and is arranged therebycushioned.

-Referring toFig. 1, the cover is shown in closed relation in full line, and in open relatlon" in dotted lines. The arc ofmovement of the connection of the upper end of the spring with the cover is indicated by the dotted line a. The spring is at least resistance when the point of connection of the upper end of the spring with the cover is in a right line between thepoint of connection of the lower end of the spring and the bracket and the pivot of the cover, the axis of the spring in such relation being indicated by the dotted line b. An are which would be described by the upper end of the spring in such tension relation having the connection of the lower end of. the spring as its center, is indicated by the dotted linec.

When therefore the connection between the upper end of the spring and the cover is moved to either side of the dotted line a, the tension or" the spring is increased, thereby acting as a counter-balance cushion when opening or closing. the cover. The cover swings to greater extent away from the ver-- tlcal plane of. its pivotv when closing the cover, causing a greater tension on the spring, and swings to less extent away from said vertical plane when placed in open relation, causing. a less tension on the spring,

the counterbalancing action of the spring being therefore proportional to its duty. The end of the extension rests against the casing when the cover is open.

- Referring to Figs. 1. 2, 3 and 11, the yoke is shown in its position for closed and .clamped relation of the cover, with the clamping rod screwed toward the cover for closed relation otthe joint '45 between the casing cylinder and the cover. If it is desired to release the cover, -the clamping rod 63 is turned for releasing its pressure on the cover and moving the block62 out of the recess 61. The yoke may then be tilted. it being provided'with a handle 81. which 'may be employed in operating and controlling the swinging thereof. swung-for opening eof the cover, the yoke will move along, the contact-facebS, as by contact of the block 62 therewith, the spring 78 acting to urge open relation of the cover until itsaxis is coincident with the dotted line a. The cover is provided with a gripf82 by means ofwhich the cover may be moved in opening and closing the same.

As theupper end of the yoke moves rearwardly, it is received in a recess .83, to vrear hen the yoke is' or" 'thepivotofthe cover, and makes contact with the t'ace'76, as by meansof the bolt 65; 7

Opening movement of the cover causes am therdescent of the upper outer'end otfthe yoke, for causing the yoke to move along the contact-face 76,'th'e reby aiding in coun terbalancing the cover andpermitting opening of the cover with little exertion. The parts are preferably arranged so that the action of thespring 78 and-the weightfot ,the' swinging endof the yoke, when the latter contacts the face 76, are suthcient to' fun ther tilt the cover into open relation with" little or no exertion, the weight of the cover if desired, beingsupplemented-by forward stress on the grip 82, the final opening move ment of the coverbeing-cushionedby the spring 7 8.. \Vhen the .cover has been tilted into full" open relation, its swinging end is preferably in-rear.of the vertical "plane in which they pivotal axis of the cover is located] H v When it .is desired to close the cover the swinging end o'f'the yoke is raised and-the I cover is, swung toward closing position. The spring'ZS acts initially as an :aid to the closing movement, until the swingingend of the cover passes. the vertical plane in which the pivotot the cover is located, and then acts as a cushion'toresist shock in 010s lated by means of'the grip. WVhen thecover has been ,lowere,d,xthe swinging end of the yoke may be still located, adjacent the-rear end of the contact face 58, adjacent the pivot of the cover. The swinging end ot the yoke is movedfover'the cover, its b-lock62 moving along the contact-face 58, aiding in urging-closing relation of the cover. i

The yoke is p-rovided with a stop 85'arranged to coact with a stop 86 onthe cover, the latter being shown-as a lug-on the arm 59, for limiting swinging movement of the yoke and positioning the clamping screw thereon with relation to the recess therefor in the cover; The clamping screw is then turned for clamping the cover in place and securely closing the cover and the casing. Y .1 a 1 It is assumed that-the casing hasbeen provided with its desired amount of plastic material, for instance, meatdough, prior to the closing of the cover.' I a 1 r r The valve=37 has in the meantime been placed'in closed relation. In order; to sup ply pressure to the under side of the press head, the valve 37 is turned into open-rela tion, whereby the aim38 is moved across the path of the yoke 48, to prevent reopening of the cover while pressure is being exerted through the valve, the arm of the yoke in this-relationbeing located'between said arm 38 -of the valve and the stop 85. The

yoke cannot therefore again be swung 'for ing the coverj; The 'cover'may be' manipu' valve 37 has been turned into-closing position, whereby the arm 38 is moved out of the path of the yoke. t

The valve 37 is shown as a conical valve, having a conical valve-plug STreceived into the. conicalsocketof the valve body 88.

The handle 39 and the arm 38" are shown as one piece in fixed relation to the valveplug li. supply'pipe- 89, leading from any suitable source of pressure, for supplying a fluid. which may be air, water, steam or other desirable pressure medium, connects with thevalve 37, and (has a pressure regulating valve 90 therein. 'The valve-body of valve '37 has a'port 91, with which the pipe 89 connects, a port 92, with which the pipe 36 connects. and a port 93 which communicateswith the atmosphere; The valveplug has ports-94, 95, 96. lVhen the ports 91, v94:, 95, 92. are in registry, pressure is being supplied to the press-head, and the arm 38 is in obstructing relation to the yoke. A pin 97 limits movement oi the arms of the valve 87. When the ports 92, 96, 95, 93, are in registry, the space in the casing under the press head is open to the atmosphere.

Convenient means are provided for cleaning the cylinder or casing. Descent of the press-head is limited by stops 101, shown as posts located in the bottom of thecasing. The casing is further provided with a clean ing opening 102, which is arranged to be closed by a cap-plate 103, by means of bolts 10 1.

Safety means are provided in connection with the cleaning means. The safety means comprise a valve/105, (See Figs. 1, 3, 4, 5, 6, 7, 8 and 9) which coa-cts with a valve-seat 106, located in the cap-plate 103, of the cleaning device. The cap-plate is shown provided with a tube 107, and the valve-stem 108 is provided with guide wings 109 coacting with the inner guide-face of the tube. A crosspiece 110 is secured to the cap-plate,

as by means of bolts 111,having sleeves 112 thereover. The sleeves are'located between the cap-plateand the'cross-plate for relatively positioning the same, nuts 113 being received over the ends of the bolts'for clamping the parts rigidly together. 'These parts extend inwardly of the cap-plate. The valve is provided with an inwardly extending guide-stem 114C, guided in a bearing 115 in the cross-plate. A spring 116 is received thereover between the valve and the crosspiece for normally urging the valve into closed relation.

The valveis arranged to be actuated by the press-head when the latter reaches a danger position or limit of movement in upward direction. These means are shown as comprising a lever 121 pivoted'bya bolt 122 toa'bracket 123 extending from the casing, and having a trip 12 1 articulated therewith at'125; Thetrip isshown as an under the press-head, and thereby acting to cause cessation of outward movement of the press-head. The inner end of the trip is preferably located inv a recess 132 in the cover, the slanting face. of the trip being continued in the recess.

The movement of the trip by the press head, upon contact of the lower portion of the inclined contact faceof the trip by the press head, is sufficient to relieve pressure I under the press-head sufiiciently to avoid damaging contact between the press-head and the cover. If, however, thecover should be open either partly or wholly and the press-head .be urged rapidly upwardly, whereby itis caused to contact the trip, the trip will'be moved an additional distance, represented by the portion of the inclined face thereof in the recess 132, thereby open ing thevalve 105 to greater extent, and creating additional relief under the presshead sufiicient to prevent thrust of the presshead out of the cylinder.

An adjustable stop 135 is provided for this safety mechanism, shown as a bolt- 136 threaded into a lug 137 in'the casing and having a threaded tube 138 thereabout, the outer end of which is arranged to becontacted by the lever 121, for limiting:movement of the lever in its direction of release position, and limiting inward movement of the trip, the nut being adjustable on the bolt for adjusting these limits of movements.

The press-head in its preferred form com.- prises an upper section 141, and a lower section 142, (See Figs. 3, 7 and 15). One of these sections, shown as'the'section 142, is provided with an annular rabbet 1 13, in which a band 14:4 is received. This band is a compressible and extensible band, and is preferably elastic. This elastic band is preferably of rubber, or of a composition having'rubber as abase. The opposite section of the press-head is provided with an annularliange 145, the inner face of which is arranged to be received about the cylindrical face of the rabbet.

The elastic band is received inthe annular rabbet. between the flange 145, which forms a shoulder therefor, and a shoulder 146 forming one of the end walls ofthe rabbet. The annular flange 145 is provided with an outer annular lip 147, and"the shoulder 1&6.- is provided with an 'outerlan i nular lip l-l8, respectively received in an; nular rabbets; 149, 150, atthe respective ends of the annular flexible band. Th lower section isshowrr provided.-

with

ceived.

justably receivedin the re ces s overthe bolt.

" iirdjustinent the nut "lengthwise of the bolt adjusts th extent of separatinglmove nient between the sections, .as will be noted by comparison between Figs. 3 and 7. The upper end of the boltand the. nut have re- 1 ciprocating movementin this recessj Contact between theplastic material and the adjustable limitingmeans is avoided by providing. a plug l59 having threaded. en.- gagement wi hthe outer. end of the wallot the recess 157. gasket 160is clamped by the plug. against an ai'inular'shoulder 161 formed in the. recess. The plug inlay be turned by a. suitable square-ended wrench received in-a hole 162 otsquarecross-section in the plate.

- tion.

The lower-section of the press-head is shown as of greater-weight than the upper section, so as to insure a dropping ofthe lower section with relation to theupper sec:-

The annular elastic band Hal is re ceived about the inner .wall-ottherabbet 143, sothat, when thesections of the press-1 head are in sep'arated relation, the elastic band. will be in stretchedjrelation in said 3 rabbe't; and preferably within the cylindri cal proiectionv otthepress-head. This relation or parts is shown inlFigs, 7 and l5, in whichthe press-head is shown at its lowermost limit ofmovernent..- f V Plastic material having been placed. in the casing ahove the :press-heachand the, cover closedand clamped, pressure. is; supplied under-the press-head through-the valve 26.. The pressure acts against the lower face of r the lower section of theup-re-ss'head, raising this lower section, resisted by the annular band or Il1l.. whereby the'el-asti'c band is compressed in axial direction for reducing the width of said elastic band and increasing its thickness, that is to sa v, its thickness and diameter are increased or spread for forcing it into intimate contact with the inner cylindrical face of the cylinder, to form. a: tight joint betweenthe press head and the wallof "the cylinder, in order to avoid passage of the pressure fluid upward ly past the plastic band and passageo't plastl'vic material downwardly past the elastic and.

; When the band'has thusbeen acted onby,

the upward pressure on. the. lowergsecftio-n of the press-head sufficientlji to support the; upper section of the -,press-he-ad1an df the weight or :the plas ic material therea we; the pressrhead will moiveupwardly, with the? sectionsof the press-head in clo-sen relation;

and the elastic band; in spread "relation, ash

indicated in Fig. 3. The upward movement.- ot the press-head will. force theiplastic ma terial throughthe nozzle or nozzles.

f .VVhen the upward movement-of the press-1 head has. been 'comple'tedhand the valve '26 is: closed to the-supply of pressure and opened to theatmosphereyth lowersectio-n or" thepress-head willdrop. to thelimitof" theperniitted separation by means-of the bolt 155 and nut 15.8, whereby the thickness and diameter of the elastic band are-again reduced to substantially therela'tion shown in Figs. 7 and 15, for permitting descent-of the press-head in'the 'cvlinder to toll'o wthe releasev or" pressure in. said cylinder; 7 p 'The cover'inay then be again opened-tor recharging the casing with additionalplas tic material, for repetition of the. opera tion.

The elastic band is made of such com s sition, for instanceiwith a rubber base, that" the liquids in the'ineat dough or sausage filling and the cleaning operations willnot, crack or harden the same. experience haw" ing demonstrated that with my improvedconstruction the elastic band retains-its life and is efi'ectivein operation for'a'very e35 tended periodot time.

I lo not herein claim the press-head hereinfshown anddescribed, having shown;

deswibed and claimed-the same in my co pending application for" Letters Patent of the United'states on improvements in pressheads for stuffing machines,- duly filed inthe United States Patent Office February 13, 1923, as Serial No. 618,877, and as a division of the present application. Having thus fully described inven-- tion what I clainr as new, and desire to secureby Letters Patent,is': 1 A

1; In ;1nechanism of the character de scribed, the combination of a casing. a ress; head in said casingta cover tor said casing at one side of saidl press-heath 'apres'sure outlet for said casing at the other "side of said press-head, a closure for said pressure outlet, an operating part for'said closure re eived in said cover, and connecting means between said operatingpart and said'closure. I

scribed, the combination of a '-casing, a

2. In mechanism of" the .character' de-j cover therefor, "a press-head in saich'casing; a pressure outlet. closure there{ for, an operating part for? said closureclosure, said cover provided with arecess for said operating part and said operating part provided with an operating face acted on by said press-head, said operating face being partially located below the plane of saidcover and partially located withinthe plane of said coverwhen said cover 1s therefor, a press-head operable in said casing, a pressure outlet in said casing, a closure therefor, an operating part, and con 'uecting means between said operating part and said closure, said operatin part provided with a operating face For coaction with said press-head to different extents when said cover is in closedposition and when'said cover is open. v 4. In mechanism of the character described, the combination of a casing, a cover therefor, a press-head operable in said casing, a cleansing opening in saidcasing at oneside or" said press-head, a cap therefor, a pressure relief opening in said cap, a closure therefor, and contact means for said press-head having operative connection with said closure for opening the same.

5, n1 mechanism of the character described, the combination of a casing, a press headoperable therein, a cleansing opening, a cap therefor, said cap provided with a pressure relief opening, a valve there-for, a

cover for said casing, an axially movable trip in said casing at' said cover, and a lever having operative connection with said casing, said tripiand said valve. f

6; In mechanism: of the character described, the combination of a casing, a presshead operable therein, said casing having a cleaning opening atone side of said presshead, a,closing cap for said cleaning open- 7 ing, a pressure relief. opening in said cap;

valve mechanism therefor including a valvestem, a bearing strip for said valve stem, means for securing said bearing strip in distanced relation to said cap, and a spring between said bearing-strip and said valve normally closing said valve; and stopping means in said casing limiting approach oi said press-head toward said valve mechan ism, said valve mechanism extending into the projections of the lines of movement of said press-head.

7. In mechanism of the characterdescribed, the combination of a casing, a presshead operable therein, a cover for said casmg, means for hingingsaid cover to said casing, and a counterbalancing spring for said cover, said counterbalancing spring having connection with said cover to coun terbalance said cover upon both the opening movement and said cover.

8. In mechanism :of

the closing movement e1" L the character de 7 scribed, the combination of a casing, a press head operable therein, a oovervfor said'cas' ing, means for hingin'g'sa-id;cover to said casing, said cover" provided :with an eXt ension extending beyond the" pivotal axis 1 of said cover, a spring, a statio narily positioned connection for said spring, and a e V 5,

connection between saidspring and sa d'extension, said last-named connection"mov Q able to both sides of a right linebetweei'r said stationarily positioned-,c-onneotion and p the pivotal axis of'said cover by therey' spectlve opening and closing movements or f said cover, whereby to cushion said cover at both its opening'and closing-movements,

9. In mechanism of the character de scribed, the combination of a casing,a presshead operable therein, a cover i'or said casing, means for hinging said cover to said casing, a yoke received crosswise of said cover, said oover provided witha'contact face for coaction with said yok e, said con-' tact-face extending lengthwise of thelpath of movement" of said yoke, and clamping means between said yoke and said cover. to

clampingly close said cover, i

10. In mechanism of the charactertdescribed,the combination of a casing, a presshead operable therein, a cover for said casing, means for'hinging said cover to said' casing, said cover provided with an extension beyond its pivotal am, and a yoke pivoted to said'casing. and-extending crosswise of said cover, said extension having resting" means for said yoke.

11. In mechanism ofthe character described, the'combination of a casing, a presshead operabletherein, a cover for'said 03S? ing, means for hingingsai d cover to said casing, a yoke pivotedto said'casing and "received' crosswise of said'cover, said-cover provided with an extension beyond its,

pivotal axis, said extensionprovided with a resting portion for said yoke, and resilient provided with a resting portion forsaid yoke, whereby said yoke 'c-oacting with said resting portion aids in'counterbalancing said cover; 4

13.111 mechanismof the character described, the combination of a'casing, a'p'ress head operable therein, a cover for said casing, means for hingingsaid cover to said casing, a yoke pivoted to said casing and straddling said cover, clamping meansbetween said yoke and said cover, said cover provided with an extension, said extension provided with a resting portion for said yoke, whereby said yoke coacting with said resting portion aids in connterbalancing said cover, a spring, a stationarily positioned connection for one end of said spring, and a connection between the other end of said spring and said extension, and arranged; whereby said last-named connection moves to both sides of a right line between said stationarily positioned connection and the pivotal axis of said cover upon the opening and closing movements of said cover.

14. In mechanism of the character de scribed, the combination of a casing, a presshead operable therein, a cover for said casing, means for hinging said cover to said casing, said cover provided with an extension beyond the pivotal axis of said cover, and a yoke pivoted to said casing and straddling said cover, clamping means on said yoke, said cover provided with a convexly curved contact face at one side of its pivotal axis and said extension provided with a concavely curved contact face at theother side of said pivotal axis, and said contact faces coasting with said yoke, and said yoke aiding in counterbalancing said cover when in coactive relation with said extension.

15. In mechanism of the character described,- the combination of a casing, a presshead operable therein, a cover for said casing. means for hinginog said cover to said casing, a yoke pivoted to said casingand straddling said cover, clamping means on said yoke, said cover provided with a coactingface coacting with said clamping means anl extending lengthwise between the pivotal axis of said cover and the swinging end of said cover, and a stop on the swing ing end of said cover'for said yoke.

16. In mechanism 7 of the character described, the combination of acasing, a presshead operable therein, a cover for said casing, pressure supply means for said presshead including. a valve, a yoke pivoted to said casing and received crosswise of said cover, and an obstructing part having con--.

nection with said valvefor location'in obstructing relation in the path of movement of said yoke upon open relation in said valve,

17. In mechanism of the character described, the combination of a casing, a presshead operable therein, a coverfor said casmg, pressure means for saidpresshead ineluding a valve, a yoke pivoted to said cas ing and extending crosswise of said'cover, and an obstructing part having operative connection with said valve whereby said obstructing part is obstructingly'placed in the path of said yoke whensaid valve is open and whereby said obstructing part is moved to be free of obstructing relation in the path.

is closed. i k 18. In mechanism of the character described, the combination ofa casing, a press of movement of said yoke when. said valve head operable therein, a cover for said cas- T ing, means for hinging said cover to said casing, a yoke pivoted to said cas ng and straddling said cover. pressure means forsaid press headincluding a valve, and an arm operable with said valve into obstructsure therefor, an operating: part, and connecting' means between said operating part and said closure, the-said press-head and the said'operating part having parts thereon relatively so formed whereby to operate said closure by means of said press-head to different extents when said cover is in closed,

position and when said cover is open. v

In testimony whereof, I have hereunto signed my name in the presence of two subscribing witnesses. p I

.OSCAR C; SCHMID'I; In presence of: i

J AMES J FiTzPATnIoK,

'DELMA VVnnNsINo. 

